There are various types of pasteurization procedures used today. Low Temperature Long Term (LTLT) processing is an intermittent process that is now only used by small dairy factories to produce some cheese products. High Temperature Short Term (HTST) treatment is a "flow" process typically carried out in plate heat exchangers and is now widely used in the production of drinking milk. The products obtained through this method are not sterile, meaning they still contain microorganisms and require refrigeration during storage and processing. Rapid pasteurization is mainly used in the production of yogurt and dairy products. There are two main internationally used pasteurization methods:
One method is to heat the milk to 62-65 ℃ and maintain it for 30 minutes. By using this method, various growth pathogenic bacteria in milk can be killed, and the sterilization efficiency can reach 97.3%~99.9%. After disinfection, only some thermophilic bacteria, heat-resistant bacteria, and spores remain, but most of these bacteria are lactic acid bacteria. Lactic acid bacteria are not only harmless to humans but also beneficial to health.
The second method is to heat milk to 75-90 ℃ and keep it warm for 15-16 seconds, which results in shorter sterilization time and higher work efficiency. But the basic principle of sterilization is to kill the pathogenic bacteria, as too high a temperature can result in significant nutrient loss.
maintenance
1. Equipment application should be managed by dedicated personnel, and attention should be paid to the operation of the refrigeration system. Operation records should be kept, and any abnormal situations should be promptly stopped for maintenance.
2. Regularly check temperature instruments and valves, and replace them promptly if any damage is found.
3. When not in use for a long time, the pipeline should be cleaned and the accumulated material and water should be drained to prevent damage to the equipment (especially the water in the pump) caused by cold freezing.
4. Check whether there are pits or damages on the inner wall of the tank.
5. Check if the mixer is lacking oil and if the oil seal is intact.
6. When the winter refrigeration unit is stopped, the accumulated water in the water condenser coil should be drained to prevent the coil from freezing and cracking.
7. Before using the equipment, the tank must be washed clean with hot water and then disinfected with steam. The materials should enter the tank through the material pipe fixed on the tank body, and the input materials should not be filled too full.
8. After the storage is completed, the remaining materials in the tank should be drained and rinsed with warm water as soon as possible to brush off any attached materials. Then, the inner wall of the container should be thoroughly cleaned with 400-500C alkaline water and rinsed with clean water.
Precautions
1. Before storing liquid materials, they should be strictly cleaned and disinfected.
2. After the liquid material is stored in the tank, the mixer should be intermittently turned on to stir, otherwise it will cause milk fat to float up, affecting the quality of the material.
3. After the material is discharged from the cylinder, all working surfaces, pipelines, plugs, etc. that come into contact with the material should be thoroughly cleaned, and no dirt should accumulate in dead corners. The outside of the cylinder should be regularly cleaned to maintain a bright and beautiful pattern.
4. Rinse the cylinder surface and inner liner with warm water, do not rinse with salt water to avoid corrosion of the equipment.
5. The reducer, motor, and bearings should be regularly oiled and lubricated.
High humidity low temperature defrosting machine
